Paper condenser.



A. PRUESSMAN.

PAPER CONDENSER.

' APPLICATION FILED AUG. 2, 1913.

Patented Feb. 9, 1915.

VVi/nesses:

/n van/0r:

UNITED STATES PATENT OFFICE.

ALBERT PRUESSMAN, OF CHICAGO, ILLINOIS, ASSIGNOR T0 WESTERN ELEGTRICCOMPANY, OE NEW YCCRK, N. Y., A CORPORATION OF ILLINOIS.

PAPER CONDENSER.

1 Specification of Letters Patent.

PatentedFeb. 9, 1915.

Application filed August 2, 1913. Serial No. 782,637.

I '0 all whom it may concern Be it known that I, ALBERT PRUESSMAN, acitizen of the United States, residing at Chicago, in the county of Cookand State of Illinois, have invented a certain new and usefulImprovement in Paper Condensers,

of which the following is a full, clear, concise, and exact description.

This invention relates to condensers and the method of making the same,and its object is to produce a condenser which shall possess increasedefliciency, and permanence and notwithstanding shall be compact andcheap to manufacture.

The invention broadly consists of a condenser in the form of a roll ofcontinuous conducting strips separated by insulating strips, but moreparticularly relates to the means for inclosing the units whereby theyare retained in their original form and size and are effectively sealed.

Referring to'the drawingsFigure 1 represents a condenser showing the canand the filling'material in cross section and the units located therein;and Fig. 2 is a section on the-line 22 of Fig. 1. r

In accordance with this invention the strips ofconducting material andinsulating material are first assembled by rolling them together to forma roll. After having boiled the units in melted paraffin wax orequivalent material, they are subjected to slight pressure on the flatsides thereof and are allowed to cool and set. The units are then placedin -a container, the space between said container and the unit beingfilled by a molten insulating substance which solidifies at ordinarytemperatures and'which is impervious to moisture, whereby the unit isretained in its original form and is protected from the deterioratingeffects of the atmosphere. i i

As this invention does not reside in the manner of forming the unitswhich may be substantially the same as that shown in Patent No. 575,653,but relates more particularly to the means of protecting the units fromthe atmosphere which tends to cause a decrease 1n-1nsulat1on therein,and

means whereby the units are caused to retain their original form andsize, thus mainhave been allowedto cool while pressure is applied to thesides thereof. I

We will now consider the method of sealing the same, wherein resides theprincipal feature of this invention. After the paraffin or othersubstance has cooled, two of the rolls 1 are secured together by unitingtheir terminals 2, as shown in Fig. 1. While only one terminal is shownin the drawings for each roll, it is of course understood that each isprovided with two in theusual manner, the terminals being connected inpairs. The two rolls thus joined are then dipped in a molten insulatingcompound which-solidifies at ordinary temperatures. This compoundpreferably includes asphaltic cement and ma also include rosin andMontan wax united in such proportions that, while it will melt at areasonably low temperature, say 400, it is sufficiently hard not to flowat normal atmospheric temperatures. I have found that a compoundcomposed of approximately 80% asphaltic cement, 8% rosin and 12% Montanwax is very satisfactory. As the quality of different samples of thesubstances used in this compound is not always the same, the exactproportions to be used in a given case can only be determined byexperimenting. By this dipping process each roll will thereupon receivea layer 3 of the insulating compound. The rolls are then inserted in acontainer 4, the .bottom of which has been covered'to a slight depth bya pouring 5 of said compound.- Care being taken to insure that the unitis equally spaced from the sides of the container, an additional pouring6 of the compound is made, extending above the terminals of the units.The container may now be provided with a cap or cover 7 through whichthe conducting strips 8 secured to the terminals 2 project.

The commercial condenser formed as above describedis of substantiallytwo microfarad capacity. If a condenser of one microfarad capacity isdesired, of course only one roll will be used. The process ofmanufacturing otherwise is substantially as just described.

In condensers as at present manufactured it has been found that theydeteriorate very rapidly; both as to capacity and insulation resistance,the deterioration in capacity being due to a loosening up or separatingof the folds or layers of the condenser, and the deterioration inresistance being due to the admission of moisture to the insulatinglayer. The method of sealing condensers herein disclosed, however,maintains the condenser units in their original form and absolutelyprevents the entrance of moisture thereto.

While the compound above described has been found particularlysatisfactory in sealing condensers, it is to be understood that theinvention is not limited to this specific compound, as other compoundsof a similar nature have been found to glve very satisfactory results.

2. In a condenser, a unit consisting of layers of conducting materialand insulation, a container in which said unit is positioned, and acompound of asphaltic cementand Montan wax surrounding said unit withinsaid container.

3,. In a condenser, a unit consisting of layers. of conducting materialand insula tion, a container .in which said unit is positioned. and acompound of asphaltic cement and Montan wax in proportions ofsubstantially eight parts of cement to one part of wax surrounding saidunit within said con- .talner.

4. In a condenser, a unit consisting of layers of conducting materialand insulation, a container in which said unit is positioned, and acompound of asphaltic cement, rosin and Montan wax surrounding said unitwithin said container.

In witness whereof, I hereunto subscribe 31st day of July, A. I)., 1913.ALBERT PRUESSM AN. \Vitnesses A. A-. W1L'rsE,. C. A. DRUSKER.

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